(1) Field of the Invention
The present invention relates in general to winding of a yarn supply package and in particular to an improved yarn supply package.
(2) Description of the Prior Art
Normally a bobbin produced on a spinning frame, particularly on a ring spinning frame, has a so-called tail yarn winding in which an end of the yarn is wound several times around a tail or head portion of the spinning bobbin in order to prevent the yarn end from being released from the spinning bobbin or to prevent the yarn end from being entangled with the yarn end of another spinning bobbin while it is transported to the next rewinding step. Further, when a spinning bobbin having such a tail yarn is to be supplied to a rewinding step, that is, to a winding unit of an automatic winder, it can be fed to a yarn end finding device in order that the tail yarn may be released in advance to enable automatic splicing of yarns at the winding unit. Examples of such yarn end finding apparatus devices are shown in U.S. Pat. Nos. 4,619,416 and 4,681,271. The entire disclosures of these patents are hereby incorporated by reference.
However, within such devices lies an inherent problem that has hindered top performance of such machines. Generally the yarn end finding device secures the thread from the spinning package and, through the use of controlled air, "sucks" an end of yarn from the spinning package into the inside cylindrical neck of the yarn package holder. When the yarn package has progressed to the next step of the operation, the yarn end is blown upward from inside the yarn package holder and received by a suction nozzle for splicing or other handling.
Few problems occur with this "blowout" step when the inside surfaces of the yarn package holder are smooth and continuous. However, the rate of "blowout" failure increases to between five and twenty percent when the yarn package holder is either made of paper, as is commonplace in the United States, or has openings along its length, for example, to permit steaming of the yarn package. When the "blowout" operation fails, the yarn package must be recycled, requiring operator attention.
A "blowout" failure can be attributed to a number of causes. For example, the inside walls of a paper yarn package holder are not finished to a smooth surface so the yarn fibers snag, resulting in a failed "blowout." Also, some yarn package holders are made with a positive doff control (PDC) that functions to restrict the yarn package holder from sticking on the spinning spindle. These holders have a perforation that fractures the inside of the wall, thereby causing a rough area very near the top of the yarn package holder on which yarns are likely to snag. Finally, some yarn package holders have a series of small (approximately one-eighth inch diameter) openings through the wall of the yarn package holder to provide for steam penetration during subsequent steaming processes. These are also likely to cause snags.
To date the only choices to correct the "blowout" failure problems have been to either purchase smooth inside wall bobbins, such as plastic bobbins, or to ream the inside surface of existing yarn package holders. However, purchasing new bobbins requires an extensive capital outlay and the reaming process appears to offer only a short term improvement since the inside surfaces of the yarn package holder soon become roughened.
It has thus become desirable to develop an improved yarn supply package that prevents snagging of the yarn end of the inner surface of the yarn end holder while at the same time eliminates high costs associated in replacing paper packages with the plastic yarn packages and eliminating short term improvement associated with reaming.